234 



FELSPATHIC AND 



TJppeh 

 Oallery. 



Wall-cases 

 6 and 7. 



83.— Felspathic porphyry, composed of crystals of 



schorl in a felspatho-quartzose base, 

 angrouz, near St. Erth, Cornwall. 



Map 33. — Rose- 



84. — Felspathic porphyry, composed of crystals of 



quartz and flesh-coloured crystals of felspar in a lighter- 

 coloured base. This forms the continuation westward of 



the Tremore Prophyry No. 81. 



It might be 



employed 



for ornamental purposes. Map 30. — Near St. Wenn 

 Cornwall. 



85. — Felspathic porphyry, composed of crystals of 

 felspar, quartz, and schorl in a felspathic base. Map 30. 



From the junction of granite and slate, near Dolcoath 

 Mine, Cornwall. 



86. — Granitic porphyry, composed of crystals of felspar 

 and spots of schorl, in a roseate felspathic base. It forms 

 part of an elvan dyke. Map 3 1 .— Creegbroaz Quarries, 

 near Chacewater, Cornwall. 



87. — Felspathic Porphyry, composed of crystals of 



light 



f< 



quartz, and schorl in a quartzo 



felspathic base. It forms an elvan dyke traversing granite. 



Map 



Croft Michel, near Crowan, Cornwall. 



■ 88. — Porphyritic granite, composed of a light grey 



felspathic base, containing crystals of quartz, flesh-coloured 

 felspar, and plates of mica. 



This forms part of a granitic dyke, extending from Grey 

 Lake, near Camelford, by Trecligoe and Helstone to Tre- 

 forde, and varies much in its mineral character ; it clearly 



Eh 



cuts the lodes. This fas well as Nos. 94, 98, &c.) is one of 



ms by the Cornish miners, several 

 varieties of which have been and still are employed for 

 architectual purposes, for which in general they are well 

 suited. At present they are employed for the corners of 

 houses, for rough buildings, walls, and for roads. Map 30. 

 Trecligoe, near Camelford, Cornwall. 



Tremor 



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